Rotary application heads for known bottle labelling installations have a rotating roller having adhesive placed two-dimensionally on certain application areas in the interior of the housing. The application areas of the rotating roller having the adhesive are then brought in contact with passing label material. In this case, the rotating roller emerges from the housing in the area of an application gap so that contact with the label material takes place immediately. Rotary application heads of this type tend to take up dirt via the adhesive covered application areas and draw it into the rotary application head.
Accordingly, it is one object of the present invention to prepare an improved rotary application head suitable for the application of adhesive to passing label material. Liquid adhesive is applied to labelling strip materials or individual labels depending on whether the printed labelling strip material is separated into single labels before passing the rotary application head or after passing the rotary application head.
The rotary application head described herein has the advantage of absolute synchronisation between the adhesive medium and the label material that is running past. Accordingly, no smearing of the adhesive with respect to the label material is possible.
In addition, a flat contact between the label material and the adhesive medium to be applied is avoided. Rather, the adhesive medium is transferred by means of a mask cylinder in a grid fashion. The adhesive medium can then flow together outside the mask cylinder through shallow recesses proximate to outlet openings on the outside of the mask cylinder. Thus, the surface areas of the label material can also be covered with adhesive.
A rotary application head that includes a rotating hollow cylinder in the fashion of a mask cylinder is known from DE 198 54 634 C1. However, the mask cylinder described in DE 198 54 634 C1 fails to emerge from the housing. The mask cylinder in DE 198 54 34 634 C1 rotates around its own axis and never emerges from the housing. Furthermore, in DE 198 54 634 C1, a compressed-air slit is associated with a slit in the housing. The slit is in the interior of the hollow cylinder or mask cylinder in the vertical cylinder. The compressed air blows out adhesive medium inserted previously into openings in the hollow cylinder or mask cylinder. Unlike the present application having a rotary application head transferring adhesive medium via contact with the strip material, the rotary application head described in DE 198 54 634 C1 is only suitable for non-contact application to passing strip material.